Preganglionic parasympathetic fibers.
In the Parasympathetic division, the preganglionic axons leave the ventral roots of the spinal cord and collectively form the pelvic splanchnic nerves.
The pelvic splanchnic nerve contains parasympathetic fibers that regulate the function of pelvic organs, such as the bladder, rectum, and reproductive organs. These fibers are involved in controlling processes like urination, defecation, and sexual function.
Parasympathetic fibres arise from S2,S3,S4. Carry preganglionic parasympathetic and visceral afferent fibres from pelvic and genital organs.
The bladder is innervated by the parasympathetic fibers of the pelvic splanchnic nerves (S2-S4) which stimulate contraction of the detrusor muscle. The internal urethral sphincter is innervated by sympathetic fibers from the hypogastric nerve, which cause it to contract and prevent urine leakage.
The autonomic nervous system nerve serving the thoracic region is the thoracic splanchnic nerve. It helps regulate functions in the abdominal and pelvic regions.
Splanchnic nerve
The vagus nerve is one of the twelve cranial nerves.
Sympathetic fibers that originate from the spinal cord levels T5-L2 form the splanchnic nerves. These fibers pass through the sympathetic chain ganglia without synapsing and project to the abdominal and pelvic viscera to regulate their functions.
The bladder receives motor innervation from both sympathetic fibers, most of which arise from the hypogastric plexuses and nerves, and parasympathetic fibers, which come from the pelvic splanchnic nerves and the inferior hypogastric plexus. Ahmed Urbizo
The pudendal nerve (part of the somatic nervous system, voluntary control) innervates the pelvic floor. It also innervates the external urethral sphincter; the internal urethral sphincter is innervated by the pelvic nerve (part of the parasympathetic nervous system, involuntary control).
The bladder is connected to both the pelvic nerves and cranial nerve X (vagus nerve). The vagus nerve innervates the smooth muscle of the bladder and contributes to its control and function. Additionally, the pelvic nerves play a key role in controlling the muscles of the bladder and genitalia.
Your kidneys control the water and electrolytes in the blood.It does not require direct brain input and will function with either transplant kidneys without innervation or in Paraplegics.The kidneys are innervated by the Vagus nerve and the splanchnic nerves as well as the pelvic nerve. These nerves seem to provide some additional regulation.The Vagus nerve originates in the Medulla Oblongata. As far as I can tell, the splanchnic nerve originates in the splanchnic ganglion, but I'm having troubles finding where else it goes.
Splanchnic organs refer to the organs in the abdominal cavity that receive sympathetic innervation from the splanchnic nerves. Some examples of splanchnic organs include the stomach, liver, spleen, pancreas, and intestines.